Patent GB-1336047-A (GB)
Title: Reforming catalyst and method of manufacture thereof
IPC: B01J23/62
Filed: 1971-04-19
Abstract: 1336047 Supported catalysts comprising germanium UNIVERSAL OIL PRODUCTS CO 19 April 1971 [2 Feb 1970] 20763/71 Heading B1E [Also in Division C5] A hydrocarbon conversion catalyst comprising germanium oxide, a Group VIII noble metal component, a halogen component and alumina is prepared by a process which comprises the sequential steps of (a) dissolving germanium dioxide in an aqueous medium at a temperature of at least 71‹C, preferably of from 82 to 99‹C, (b) commingling a soluble Group VIII noble metal compound with the resulting solution, (c) impregnating alumina gel with the resulting solution and (d) heating the impregnated alumina gel initially in an oxidizing atmosphere at a temperature of from 427 to 593‹C, whereby the germanium and Group VIII noble metal components are converted to the oxide form, and thereafter in a reducing atmosphere at a temperature of from 371 to 593‹C, preferably for a period of less than two hours, whereby the germanium component is retained in the oxide form and the Group VIII noble metal component is reduced. Impregnation may be effected by immersing the alumina gel in the solution for at least fifteen minutes under quiescent conditions, the impregnated gel thereafter being evaporated to dryness. The reduced material may be treated at a temperature of from 10 to 602‹C with a gas mixture comprising hydrogen and a sulphur-containing compound, for example hydrogen sulphide, an organic sulphide or a mercaptan, to incorporate from 0.05 to 0.50 weight per cent of sulphur in the material. The catalyst may contain from 0.5 to 1.0 weight per cent of germanium dioxide, from 0.1 to 1.0 weight per cent of Group VIII noble metal and from 0.1 to 1.5 weight per cent of halogen which may be derived from halogen present in the alumina gel and/or in the solution used to impregnate the alumina gel and/or in the oxidizing atmosphere which may contain, during at least part of such calcining step, halogen or a halogen-containing compound, for example hydrogen chloride, and optionally water vapour. The Group VIII noble metal may be selected from rhodium, ruthenium, palladium, osmium, iridium and platinum; the halogen of the halogen component may be selected from fluorine, chlorine, bromine and iodine The alumina, which may be naturally-occuring or synthetically - prepared alumina, may be selected from gamma-alumina, eta-alumina and theta-alumina and may be in the form of spheres, pills, granules, extrudates or powder; a preferred alumina is gamma-alumina having a surface area of from 150 to 500 m<SP>2</SP>/g, an apparent bulk density of from 0.30 to 0.70 g/cm<SP>3</SP>, an average pore diameter of from 20 to 30 Angstroms and a pore volume of from 0.10 to 1.0 cm<SP>3</SP>/g. According to the single example, catalyst is prepared by dissolving germanium dioxide in water at 74‹C, adding chloroplatinic acid and concentrated hydrochloric acid in succession to the resulting solution, maintaining the resulting solution at 74‹C for 15 minutes, filtering the solution while hot, immersing 1.6 mm diameter spheres of gamma-alumina (prepared from basic aluminium chloride hydrosol by a conventional oil drop procedure) in the hot filtrate, maintaining contact between the spheres and filtrate for 30 minutes under quiescent conditions and subjecting the impregnated spheres successively to drying at 199‹C in air, heating at 524‹C in dry air containing hydrogen chloride, heating at 524‹C in dry air, purging with nitrogen and reducing at 566‹C in a hydrogen stream for 1 hour.